


Three's Company

by Sincestiel



Series: Tumblr Prompts [2]
Category: Supernatural
Genre: Anal Fingering, Anal Sex, Blow Jobs, Established Relationship, First Kiss, First Time, M/M, Multi, Sibling Incest, Threesome, Threesome - M/M/M
Language: English
Status: Completed
Published: 2016-10-10
Updated: 2016-10-10
Packaged: 2018-08-21 17:48:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,376
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8254849
Author URL: https://archiveofourown.org/users/Sincestiel/pseuds/Sincestiel
Summary: “Come ‘ere, Cas,” Dean beckons from his bed, one finger lazily trailing up and down Sam’s naked back.  Sam shivers, either at the touch or at Dean’s invitation.  But he doesn’t say anything.  Gives no indication that he wants Castiel to join them.  Neither does he indicate he wants Castiel to leave.  He just stares, hazel eyes watching him curiously, wondering what he’ll do.  What he’ll make of them.  Like this.





	

**Author's Note:**

> Another tumblr prompt. I didn't get every detail of this one just right. But it was definitely inspired by this prompt and certainly fairly close to the request. Sorry, anon. I tried.
> 
> Can I ask for domestic wincestiel in the bunker with top Dean, subby-bottom Sam and Casiel pov?

“Come ‘ere, Cas,” Dean beckons from his bed, one finger lazily trailing up and down Sam’s naked back. Sam shivers, either at the touch or at Dean’s invitation. But he doesn’t say anything. Gives no indication that he wants Castiel to join them. Neither does he indicate he wants Castiel to leave. He just stares, hazel eyes watching him curiously, wondering what he’ll do. What he’ll make of them. Like _this_.

But Castiel isn’t surprised. He knew this aspect of the relationship existed. He’s always known. And they hide it less now that they’re all settled down together. Castiel has walked in on touches and sometimes watched them scramble away from each other when he caught them on the tail end of a kiss. But this? Them naked and obviously mid coitus is Dean’s bed? This is a new scene. Something he has never beheld.

Sam is stretched out on his stomach, the sheet resting precariously on the swell of his backside. His back is tan and muscular, his arms are corded, and his face is soft, hair falling over one eye and the other almost pressed into the pillow. And Dean is on his side, pressing his front into Sam’s flank, one long, strong leg bent, no clothes in sight. One tiny move and either one of them could be fully exposed. 

They’re beautiful.

Dean is still staring at him, still holding a hand out. And Castiel may sometimes still miss slight nuances in human communication, but there is no doubt here. He is certain of what Dean is offering. He’s imagined this before even, being invited into Dean’s bed, his arms. And in every one of the fantasies, the old ones when he only had a vague idea of what it would mean and the fresher ones where he not only knows what it would entail, but has some ideas of his own, he said yes without hesitation. 

But none of them ever involved Sam, despite knowing what Sam was to Dean. Castiel just always imagined Dean would keep then separate. Castiel would just be thankful for any attention Dean bestowed on him. And he wouldn’t dream of trying to come between the brothers (because that never worked well for anyone and Castiel didn’t mind sharing Dean anyway, as long as he got to have him too). And Sam was used to Dean having other partners, occasionally had others himself. So Castiel wouldn’t be a threat to him.

But Sam is here. Solid and huge where he’s resting almost under Dean’s body. So quiet and so still. Just studying Castiel and waiting for his answer. Castiel cocks his head, focusing entirely on Sam, trying to get a feel for what he thinks about this. But with his power waning and, apparently Sam’s sheer determination to give nothing away, Castiel just ends up staring at him. And Sam stares right back, hands shoved under the pillow, shoulders pulled tight but also somehow, relaxed. Like Dean, he’s just waiting. And whatever choice Castiel makes will be fine.

Dean huffs, humored but also impatient, and Castiel looks back up at him. There’s a very dark, knowing look in his eyes and Castiel takes one step forward, always inexplicably drawn to this man, before he stops. Still so unsure about Sam and unwilling to intrude or hurt him in any way. Because Sam is so important to Dean, so by default he also became important to Castiel. 

“Sammy,” Dean murmurs, breaking the strange silence they’ve been swimming in for several long minutes while Castiel hangs in his limbo, “He’s worried you don’t want him here, that you’re going to be jealous or hurt.” Dean, for all that he would deny it, is very perceptive when it comes to human emotion. Particularly when it involves Castiel or Sam. It’s unnerving sometimes how well he can read them.

“Why don’t you show him how wrong he is, huh?” Still holding eye contact with Castiel, Dean leans over to kiss the top of Sam’s head and pats one plump cheek. Sam’s nod is barely there, but he lifts up, pectorals and abdominals rippling as he rolls over and swings his legs off the bed. And he is naked, completely. He’s also hard. Long and thick and Castiel can’t take his eyes off of Sam’s groin. He truly is a work of art.

Sam stands and then Castiel can admire the full length of his sculpted body and he totally understands Dean’s weakness when it comes to Sam. It’s no wonder Dean was able to cast his morals aside to have this man in his bed. Brother or no, Castiel doesn’t know if Sam can be resisted. Because, as he moves closer, Castiel is certainly responding to him. Eagerly.

Sam reaches out for him then, pulling Castiel closer by his arm to help close the distance between them. And then Sam is right there, almost against him, their chests brushing when either of them breath deeply. Castiel can feel the heat radiating off of him through his clothes – suit and trench coat, because he’s just come in from outside.

“Stay,” Sam says softly, placing a big hand on Castiel’s jaw and tilting his head so that Castiel is looking up into those hazel eyes. His other hand starts tugging at Castiel’s coat, inching it down his arms, “Dean’s been dying for you to join us.”

Dean lets out a bark of incredulous laughter from behind Sam, still propped up on his side, sheet draped over his midsection now. “Only me, Sammy? Really? That how you’re telling it?”

Castiel’s eyes dart between them, vision going slightly blurry when he looks up at Sam because he’s so close. And because he can, because it doesn’t seem like Sam will reject him right now, Castiel lifts a hand and places it cautiously on Sam’s waist and finds the skin soft and warm. But Sam’s reaction is interesting. He shudders under Castiel’s touch. The same way he does when Dean throws a possessive arm around his waist, or a steadying hand over the small of his back. And like it weakens him in some way, Sam leans down, rests his forehead on Castiel’s, sharing air and running his thumb over Castiel’s mouth.

“Dean?” Just his brother’s name. It shouldn’t even be a question because it doesn’t make sense on its own. But Dean must hear something unspoken in it. Something that makes it a reasonable and complete thought.

“Yeah, Sammy. Toldja you can already.”

“Cas?” Sam asks, and then, because he must remember that Castiel lacks the ability to communicate with him in single syllables and thoughts that aren’t voiced, “I’m going to kiss you now, okay? And then I’m going to get you out of all of these clothes. Dean… _We_ would like for you to… I want-”

“What Sam is trying to say,” Dean starts, up off the bed now and approaching them, also stark naked. And Castiel would really like to admire the view because even in his peripheral it’s stunning. But Sam is still right there, breathing shakily over Castiel’s mouth, the promise of a kiss dangling between them. And then Dean is behind him, right up against his back and Castiel can feel Dean’s erection poking at the base of his spine.

“Is that we really want to fuck you, Cas. Both of us. And yeah, Sam wants you here too. Has for a while now,” Dean finishes, his lips brushing over the shell of Castiel’s ear, warm breath ghosting over the sensitive skin of Castiel’s neck.

That’s all the encouragement Castiel needs. He just needed to know he was welcome by both of them. And so he pushes up to the balls of his feet, making him just tall enough to meet Sam’s lips with his own. Sam opens to him instantly, their tongues brushing gently as Dean’s hands grip at Castiel’s hips. And the groan Castiel hears comes from behind him. Dean likes watching them.

“Come on, Sammy. You can do better than that.”

Castiel thinks Sam is doing just fine with little kitten licks against the roof of Castiel’s mouth and tiny nibbles at his lips when they need to breathe. But Sam doesn’t seem offended at the criticism. Instead his lips pull tight in a smile that’s so contagious Castiel smiles back, opening his eyes – not even sure when he closed them – to see a mischievous glint in Sam’s eyes.

“Why don’t you demonstrate for me, Dean?”

Castiel never thought of sibling rivalry as attractive but when Dean turns him, holds him close with one hand over the small of his back and the other tangled in his hair, and then kisses him like he’s dying for it, it suddenly is very arousing. 

Sam’s kiss was sweet, tender even. Slow and soft. Dean’s is deep and demanding; he takes control immediately and maintains it with his tongue and teeth. And the whole time Dean is plundering his mouth, swallowing every sound Castiel makes, Sam is tugging at his clothes. It feels like seconds and he’s bare chested against Dean with Sam kneeling behind him working him free of shoes and pants as well.

As soon as he is naked, there are hands everywhere. Sam and Dean massaging and caressing his flesh from calves to the top of his head. And Castiel is just clinging to them, so overwhelmed. He’s had sex before, so it isn’t being with another person like this that makes him dizzy and unsteady. But being with them, _both_ of them, that has him out of sorts. He’d always hoped he’d get to this point with Dean. But the thought that he could have Sam too, that they could share something so amazing and all-consuming never occurred to him.

And it is all-consuming. He doesn’t even realize they’re moving toward the bed until Sam is pulling him down, Dean following after, his mouth attaching to the skin just under Castiel’s jaw as Sam arranges them on the almost too small space. And then there are slick fingers prodding at his entrance. He’s not even sure which one of them it is until Dean speaks.

“That’s it, Sammy. Open him up. Good boy,” Dean grits out into Castiel’s neck, followed by, “Me or Sam, Cas?”

It takes Castiel a while to realize that Dean is talking to him. He’s lost in the feel of Sam’s long fingers pressing into him, stretching him open, and Sam’s mouth is nibbling at his shoulder. And then Dean is flicking his tongue against one nipple and then the other while his hands trail softly over Castiel’s skin. And Castiel is still just hanging on, fingers digging into Dean’s arms, head thrown back over Sam’s shoulder, and his hips are driving down, trying to take those clever fingers even deeper.

“Cas, baby, you gotta answer me here. Who do you want inside you. Me or Sammy? It’s up to you.”

“Both of you,” Castiel answers without even thinking about the implications of what he’s requesting. Dean does think about it though and lets out a low chuckle.

“That sounds awesome. And we’ll totally do that sometime. But that’s a bit much for your first time,” Dean stops there and Castiel can tell he’s considering his own words when he lifts his head from Sam’s body to meet Dean’s gaze, “Unless… unless this isn’t a first for you. Which is okay. If someone was… um… here first.”

Sam’s fingers pull out and Castiel wants to whine and chase them down. But Dean is speaking to him, and he needs to focus. So he lets Sam’s glorious fingers leave.

“No,” Castiel hurries to assure Dean. Because to him it’s important, even if Dean really doesn’t care, “Not like this. And you, please. If that’s okay with Sam.”

“Sammy’ll be fine. Won’t you, Sam?”

Castiel feels Sam’s nod and his answer rumbles against his back, “Yeah, Dean. Want to watch you.”

There’s something off about the way he’s talking to Dean. Deferring to him in a way he rarely does. Something about it causes Castiel’s body to heat. And that heat is amplified when Dean praises Sam, so sweetly.

“Good boy, Sammy. I’m gonna give you a front row seat. Help Cas get up on his knees and you turn around here for me, under him.”

Sam nods again and then there’s a flurry of movement. Dean manages to press several kisses to both his lips and Sam’s and then Sam kisses him deeply for several seconds until Dean clears his throat and Sam pulls away with a final nip to Castiel’s bottom lip.

Then Sam is under him, face inches from Castiel’s hardness and Dean is behind him, hands clutching at his hips. And just before Dean nudges at his entrance, Castiel understands why they’re positioned like they are. Dean is going to… penetrate him while Sam takes him into his mouth. He has just a moment to think this is a horrible idea if Dean is expecting any sort of stamina from him. But he doesn’t get a chance to express that thought because Dean starts to slowly press into him just as Castiel feels the first swipe of Sam’s tongue.

It feels so good. So very good, that Castiel doesn’t know what to do with himself. As Dean inches in little by little and Sam kisses and licks over the head of his penis, Castiel digs his hands into the sheets. Tries to force himself not to come. Has to find some kind of distraction. And his eyes land on Sam’s rather large erection. It’s wet at the tip, more leaking out with every moan or hum that Sam’s releases between his legs. And Castiel makes a decision. He needs to get his mind off the immense pleasure these men are causing. So he leans down and takes just the head in his mouth, swirls his tongue over it to collect and taste the liquid beading there.

The sound Sam makes is almost pained and Castiel feels a hand in his hair, tugging. It’s Dean because Sam’s hands are trapped where they’re gripping the backs of Castiel’s thighs. He succeeds in pulling Castiel’s mouth away from Sam, but there’s no aggravation in his voice when he speaks.

“Don’t have to do that, Cas. Sam will be okay until we’re done and then I’ll take care of him.”

“Need to,” is the only response Castiel can voice and Dean loosens his hold on Castiel’s hair, but doesn’t let his mouth sink down again just yet.

“That okay, Sammy? Cas wants to suck your dick, baby. You good with that?”

“Yes, God yes. Please, Dean.” Sam sounds desperate for it but Dean is still holding Castiel’s head away from Sam. But, thankfully, he’s also very still inside of Castiel and Sam is just breathing over his sensitive flesh. So the need is so urgent for him at the moment. 

“May I, Dean?” He asks, hearing how breathy he sounds even to himself. When Dean doesn’t answer right away, Castiel throws Dean’s crude words back at him, “May I please suck Sam’s dick?”

“Oh fuck,” Dean growls, involuntarily shoving himself the last few inches into Castiel. Which makes Castiel grunt because he’s suddenly full of Dean. And it feels so good he might actually shed tears.

“Make him come, Cas. Take care of Sammy for me.”

He doesn’t know why he answers the way he does, but when it earns him his first thrust from Dean and a whimper from Sam, he’s glad he does, “I’ll take care of Sam, Dean. Always.”

And then there’s no more talking short of the occasional expletive. Dean releases Castiel who takes Sam back into his mouth as deeply as he can. And Sam swallows him too. Then, like he knows Castiel needs the guidance, Sam starts slow and easy, letting Castiel copy every movement. That helps too, he concentrates on letting Sam teach him how to please him and he’s able to keep himself from ejaculating too early.

Castiel isn’t even sure how long they writhe together on the bed. Usually he’s good with time, guessing and estimating. But in some ways it feels like the carnal pleasure lasts for eons and in some ways it feels like they’ve barely just begun. 

He and Sam have worked out the perfect rhythm that allows them to compensate for Castiel’s rocking body, and Castiel is lost in it when it changes without warning. Dean’s movements change from long, deep thrusts, to short grinds of his hips and his voice breaks on a gravelly groan and Castiel knows what’s happening. Dean’s orgasm lasts longer than Castiel would have expected, and he’s amazed that he can actually feel every pulse of his erection as he empties into him.

And, like Dean’s pleasure triggers Sam’s, Sam pulls off Castiel with an urgent, “Shit, Cas, I’m gonna come.” And then Castiel’s mouth is being filled and he remembers something he saw in one of those movies Dean likes to watch. So he swallows several times, consuming all that Sam offers him. And something about it must be surprising to Dean because he sounds gobsmacked when he whispers to Sam.

“Did he just…” He trails off and Sam replies in the affirmative, winded and wrung out.

“Oh my God, come ‘ere, Cas.”

The bed is too small for all three of them to move around too much, but somehow Sam rolls out from under him and Dean slips out of his body and then they’re all twisting and turning. Castiel hisses every time Dean or Sam brush against his turgid length, but Dean keeps mumbling assurances that he’s going to tend to him in between orders than Sam follows without hesitation. And they’re able to get Sam against the headboard with Castiel sitting between his spread thighs. At the gentle pressure of Dean’s fingertips against his sternum, Castiel leans back into Sam’s chest. Sam’s muscular arms slide around his waist, just out of reach of his jutting erection.

And then Dean crawls over him, melds their lips together and chases every trace of his brother he can find in the crevices of Castiel’s mouth. And his hands roam freely over Castiel’s body, possessive and sure, but also desperate. And something feels thick in the air between them. It hits Castiel then, as Dean leaves his mouth, dropping wet kisses and sharp little nips down his body, that Dean has been longing for this too. The thought makes him whimper and Dean and Sam both answer with growls and tightened limbs, clutching him to them as if he might want to run. The idea is absurd. He could never leave either of them. And he means to voice that, but Dean’s lips wrap around his arousal and he can’t produce anything more than pleading moans and soft sighs.

When Castiel’s orgasm takes him, it’s more intense than any of the few he’s experienced in the last few years. His body snaps taut and a sound akin to a wail rips its way out of his throat and his entire focus narrows down to the feel of Dean’s warm mouth and the wicked tongue lapping at his release even as it spurts from his body. And the he goes limp in Sam’s arms and Dean pulls off, now just nuzzling sweetly at Castiel’s groin, one hand digging into his knee and the other carefully cradling Castiel’s testicles. He thinks he could stay just like this for hours. Maybe for all eternity.

But he only gets a few minutes before Dean grunts and lifts himself up, wincing when the bed threatens them with a few loud creaks. “We need a bigger bed. Think a California King would fit in here, Sammy?”

Sam hums and nods, but his attention seems to all be on Castiel. His hands are rubbing soothingly at Castiel’s stomach and side and he’s pressing soft kisses into Castiel’s hair. It’s sweet, how needy he seems to be right now. Castiel smiles and Dean rolls his eyes.

“He’s a cuddler, Cas. All clingy arms and roaming hands after he comes. I swear he’s a fucking octopus.”

Sam laughs, but his hands and his mouth keep going, completely unashamed. Castiel finds that he likes it and burrows deeper into Sam’s arms, pushing into every caress.

“You too, huh? Good. You can keep each other satisfied in that department and I can go shower.”

With that, Dean stands, still naked, still breathtakingly beautiful. And Castiel feels a feeble stirring from his crotch. Dean must notice a twitch or the blush rising up his neck, because he smirks like he knows just exactly what Castiel is thinking.

“You might be able to get it up again right now, but the refractory period for humans is longer. Especially humans my age. So I’m gonna shower and you snuggle Sammy.”

It always catches Castiel off guard when he is reminded that Dean still thinks of him as an angel. But, while he does still have some of his ‘mojo,’ he’s nearly as human as Sam or Dean these days. But he doesn’t correct Dean. The one time he tired, Dean was adamant that Castiel would always be an angel, whether heaven welcomed him or not.

Dean plants a kiss on the tops of their heads, and whispers to Sam, “Whatever you want, baby. No rules with Cas,” and then he slips out the door and it’s just them.

It’s odd, being intimate like this alone with Sam. Mostly because he never imagined it as a real possibility. He should have though, he thinks. Because they’re a package deal. At least if you want either of them for more than just sex. And Castiel does. At first he thought it was just Dean. But now, being held in Sam’s embrace, he’s not so sure. Maybe a part of him has always been fascinated by SamWinchester.

“You’re thinking too hard, Cas. What’s going on in that pretty head of yours?”

Rather than express thoughts and feelings he still doesn’t fully understand himself, he shifts back to Dean’s parting words.

“Rules?”

For some reason, he expects Sam to be embarrassed or to try to change the subject. Dean always does that if the conversation veers into sexual or emotional territory. But this is Sam. And Sam tempers and balances out his brother in every way. So of course he explains without holding back. 

“Yeah. If I sleep with someone else and Dean isn’t there to tell me what to do, I have rules I have to follow. I’m not allowed to kiss anyone else. And I can fuck, but I can’t be fucked. Dean has the same rules. But we decided a while ago that, if we ever got you here, the rules didn’t apply to you.”

“While we were,” Castiel starts, unsure of what he wants to say or how to ask. Years of navigating his odd relationship with Dean has left him sometimes unsure of what is and what isn’t appropriate to discuss, “Dean seemed to be in charge. You deferred to him. Is that intentional?”

Sam snorts and buries his nose in the top of Castiel’s head as he pulls the sheet up and over them. “Yes and no. It didn’t start intentionally. It’s just that Dean is my big brother. And when we first started… um… _this_ , he was more experienced as well. So it was habit to look to him for guidance. But now it’s more intentional. We don’t have, like, a standard dom/sub thing going. Just, kinda, our own thing.”

Castiel nods because that makes sense. But it also raises other questions. About himself and how he fits in their dynamic. “And what about me? Would I be expected to submit to Dean? Or you? Or is it too presumptuous of me to think this might continue past today?”

“You don’t have to submit to anyone if your don’t want, Castiel. I don’t want your submission myself. And you can work that out with Dean yourself. But you’ll probably have to do that in the bed because you know he isn’t going to actually talk about it.”

Castiel smiles because he does know how much Dean prefers actions to words.

“Look, Cas, here’s the deal, Dean is in love with you. Like hardcore, fell hard and fast, pining over you in love. And he also loves me. I don’t mind sharing him if you don’t. And I liked having you here with us just now-“

And Sam doesn’t get to finish his sentence because Dean practically bursts back into the room, dripping wet and out of breath like he rushed through his shower to get back to them. His towel is slung low on his hips and he’s drying his hair with another, but he extends one finger to point at Sam for a second.

“You’re telling it like you haven’t been obsessed with him since the first time you met him. ‘Don’t mind’ my ass. You’ve gotten off several times to me talking about seducing Cas. Tell it right or don’t tell it at all, Sammy.”

Sam huffs, but then he’s using his hands to guide Castiel to roll over facing him. And they’re all limbs until Castiel finally settles straddled over Sam’s thighs. Their groins are snug together and Castiel thinks Sam’s recovery time might not be as long as Dean’s. 

He expects Sam to say something because that what Sam does. But he doesn’t now. Instead an he reaches up with both hands, one on either side of Castiel’s neck and pulls him down into a heated kiss. Soon enough they’re grinding together and Sam is pulling back just far enough to murmur, “Yeah. Had a thing for you since forever.”

Castiel smiles against Sam’s mouth, his hands clinging to Sam’s sides, and he nods slightly, replying, “I have a _thing_ for you, Sam. Dean too.”

Sam laughs softly, pulling Castiel’s bottom lip into his mouth and the bed dips behind Castiel. Dean slots himself against Castiel’s back, warm and damp, and Castiel has just enough time to think Dean’s shower was a waste before he loses himself to the brothers’ attentions.

**Author's Note:**

> Customary tumblr plug: Hey, if you wanna follow me on [tumblr](http://sincestiel.tumblr.com/) that would be alright. I don't post much there yet, but I'm considering taking prompts. But that just depends on if anyone is interested. Shoot me an [ask](http://sincestiel.tumblr.com/ask) if you have a prompt and we'll see what happens. :)


End file.
